Due to the rapid advancement of technology, the number of products incorporating digital technology is rapidly increasing. For instance, various digital products including DVD players, cable set-top boxes (STB), digital video cassette recorders (DVCR), digital TVs (DTV), personal computers (PC), etc. may be connected to a common network. These stations may implement various protocols to exchange audio-visual and other data with stations on the common network.
The IEEE 802.15 Working Group is establishing a standard for a WPAN that may include mobile and stationary stations within close proximity and is actively attempting to apply this standard to home automation systems, remote control systems, ubiquitous sensor networks, etc. Specifically, the currently standardized IEEE 802.15.3 is named HR-WPAN (high rate-WPAN) and specifies a wireless communication network capable of a high-speed data transfer rate over 55 Mb/s. HR-WPAN includes short range communication between 5 and 55 meters for wireless multimedia transfer in a home network, a data transfer rate over 55 Mbps, dynamic configuration of network topology for element stations, time division multiple access (TDMA) support for quality of service (QoS) tiers and data stream security, peer-to-peer connectivity, etc.
The WPAN includes a coordinator that provides the basic communications timing in the WPAN, including transmitting a beacon signal, and the coordinator may manage the QoS requirements of the WPAN. The WPAN coordinator needs a WPAN-wide power saving scheme for the following two reasons.
First, in an IEEE 802.15.3 network, a network access point (AP) as found in a 802.11 network is not found. This is because a WPAN-series network is a peer-to-peer network including a dynamic topology based upon the WPAN enabled stations in range of the WPAN network. Hence, a fixed AP is not contemplated.
Second, a WPAN station functioning as the coordinator may be one of the large variety of devices. Each of these various stations may have different standby states based upon their design, operation, and power requirements. Therefore, the power saving modes of the various stations may be very different from each one another. Hence, power management of the WPAN by the coordinator is desired.